612 DR THOMAS R. ERASER ON THE ANTAGONISM BETWEEN 



elevation (an elevation above that represented in the diagram), and either there 

 or somewhere further in advance, it will meet the portion of the line forming the 

 lower boundary of this region, and in this manner the boundaries of the 

 region of recovery would be completed. 



General Characters of the Symptoms produced by different Combinations of 

 Atropia and Physostigma. — In the account that has been given of the experi- 

 ments contained in this section, I have avoided all details of the nature of the 

 symptoms that were produced, believing that any special allusion to them would 

 probably have distracted the attention from the primary purpose of this portion 

 of the research. Further, the minute details of the kind that in the previous 

 section were in many instances given were not concerned with experiments per- 

 formed at any special portions of the region of recovery, nor in any instance 

 with experiments performed in the region of death. The experiments in each 

 of these regions may be divided into two great classes, in accordance with the 

 symptoms which they presented. In the one class, certain of the effects of 

 atropia were prominently developed and maintained for considerable intervals, 

 while the effects of physostigma were but slightly, or even not at all exhibited. 

 In the other class, several of the effects of physostigma were present in a decided 

 form, and masked either completely or in part the effects of atropia. 



In the first and second series, the former class of symptoms characterised 

 the experiments where recovery followed the administration of a large dose of 

 atropia, and also those where death followed the administration of an excessive 

 dose of this substance. The latter class of symptoms were present in the experi- 

 ments where recovery followed the administration of a small dose of atropia, 

 and also in those where death followed the administration of a dose of atropia 

 insufficient to counteract successfully the lethal effect of the dose of physostigma 

 given in combination with it. 



In the third series, after both substances had been administered, atropia 

 effects were most distinctly produced in the experiments where recovery 

 followed the administration of a large dose of sulphate of atropia simultane- 

 ously with, or five or ten minutes after the dose of physostigma there given ; 

 and also in those where recovery followed the administration of the larger of the 

 doses of sulphate of atropia that were given before this dose of physostigma, 

 provided the interval of time separating the administration of the two sub- 

 stances were not a very prolonged one. These effects were likewise promi- 

 nently displayed in the experiments where death followed the administration 

 of an excessive dose of sulphate of atropia simultaneously with, or five or ten 

 minutes after, the physostigma; and also in those where death followed the 

 administration of from 3 9 to 5 grains of sulphate of atropia before the physo- 

 stigma at an interval of time too short to permit of successful antagonism. On 

 the other hand, the effects of physostigma were in this series most prominently 



